I. Field
The following description relates generally to wireless communication systems and more particularly to techniques for interference control in a wireless communication system.
II. Background
Wireless communication systems are deployed to provide a multitude of communication services such as voice, video, packet data, broadcast, and messaging services as well as others. These systems can be multiple-access systems capable of supporting communication for a number of terminals by sharing available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, as well as other systems.
Wireless multiple-access communication systems can simultaneously support communication for multiple wireless terminals. In such systems, each terminal can communicate with one or more sectors through transmissions on the forward and reverse links. The forward link (or downlink) refers to the communication link from the sectors to the terminals, and the reverse link (or uplink) refers to the communication link from the terminals to the sectors. These communication links can be established through a single-in-single-out (SISO), multiple-in-single-out (MISO), and/or multiple-in-multiple-out (MIMO) systems.
Multiple terminals can simultaneously transmit on the reverse link by multiplexing their transmissions to be orthogonal to one another in the time, frequency, and/or code domain. If complete orthogonality between transmissions is achieved, transmissions from each terminal do not interfere with transmissions from other terminals at a receiving sector. However, complete orthogonality among transmissions from different terminals is often not realized due to channel conditions, receiver imperfections, as well as other factors. As a result, terminals often cause some amount of interference to other terminals. Furthermore, because transmissions from terminals communicating with different sectors are typically not orthogonal to one another, each terminal can also cause interference to terminals communicating with nearby sectors. This interference can result in a decrease in performance at each terminal in the system. Accordingly, there is a need for effective techniques to mitigate the effects of interference in a wireless communication system.